Yielding power-coupling.



No. 879,286. PATENTED FEB. 18, 1908.

W. C. MAYO -& J. HOULEHAN.

YIELDING PWER COUPLING.

APPLICATION FILED MAY 7, 1907.

Alf@ i.

4 TTORNEYS UNITED sTATEs PATENT OFFICE.

WILLIAM C. MAYO AND JOHN HOULEHAN, OF EL PASO, TEXAS, ASSIGNORS OFONE-THIED TO GEORGE E. BRIGGS, OF BARSTOW, TEXAS.

YIELDING POWER-COUPLING.

i No. 879,286.

Speccation of Letters Patent.

Patented Feb. 1s, 190s.

Application led May 7l-1907. SerialNo. 872.337.

To all whom it may concern: l

Be itvknown that we, WILLIAM C, MAYO and J oHN HOULEIIAN, citizens ofthe United States, residing,r at El Paso, in the county of der which. itis designed to operate.

In traction systems it is advantageous to provide the cars withindividual power units whereby each car becomes independent of everyother car of the system. It is also advantageous in such a system thatthe explosive type of engine be used as the power element. Such powerunits are best operated when allowed to run continuously, whether thecar be moving or standing still, and for the purpses of the system towhich this invention most closely relates such a car unit should have apractically constant speed irre spective of the powerdemanded in therunning of the car. However, under the condi.-

tions of traffic, the car must run at various speeds and thus bring upontheY power unit various loads from time to time, and at other times thecar must be brought to a standstill7 and then again must be started. Allthese` various conditions of the operations of the cars of a tractionsystem reduce a great variety of strains and sur den demands for powerand also sudden periods when no power is required, thus subjecting thepower unit to all sorts of variation of demand for speed.

The use of friction clutches as the intermediary Jfor transmitting powerfrom the driving element to the driven element isout of the uestionsince they are largely unreliable for t e transmission of such heavypower as it is designed to use at times upon .the cars of Y our system,and since such clutches require constant repair andare in many ways notat all adapted Jfor our purposes.

Our system contemplates the use-of a constant speed driving elementgenerating power in accordance with the demand, and in connection withsuch driving element we enntemplate the use of means for changing fromone speed to another. Undersuch condittions the cars are liable to besubjected tomore or less sudden shocks, which are injurious to both theengine and the driving gear.

It is the object of the present invention to counteract these injuriouseHects and to cushion the shocks so thatv there is a certain elasticityor flexibility between the driving element and the driven elementwhereby the changes of speed or the effects of variation in the demandfor power are not instantly transmitted from one element to the otherbut be come effective `only after a certain period of time, whereby theshocks are so distributed through such period of time that theequilibrium between the driving element and the driven element isgradually and not ,suddenly restablished.

To this end, the invention comprises .an

elasticor yielding connection between the driving element and the drivenelement j which will yield in' proportion to the power demanded and willthen tend toestablish an equilibrium between the two elements withouttheir being subjected to any shock or jar.

vThe invention comprises a drive shaft which ma receive power from` asuitable source, suc for Instance, as an explosive engine of vsufficientreserve power, and a driven shaft connected tothe part which is toreceive power from the en ine whether this driven part be the drive weels of a traction car or some intermediary part` connected to saiddrive wheels, or whether any other driven element be included. These twoshafts are in constant fixed relation .one to the other. Upon them ismounted a sleeve havin longitudinal movement with relation to t e twoshafts, the\ said sleeve being positively fixed to one 'shaft forrotation therewith and the other shafthaving means whereby it may becoupled to the sleeve for rotation therewithl or released from thesleeves so that the sleeve and last-named shaft may rotate relativelyone tothe other. Elastic connections 'gare provided. and means are alsofp'rovided for putting these elastic connections undery more or llessstress so that the driven member under increased load may have a certainla movement which will be gradually eliminate until synchnonism oflrotation yis established,

ions will m y asiessfst when the deieiess'ened.' y @is hy no Ineenslimited to 'oints which-have just been t. 'comprises numerous i'eahefully understood from 'the d''description taken in con- .i",accornpanyhig drawings partei is'speciication', in Which,-.

v,is a'longitudinal section, with ini eration, of the improved power g 2is a longitudinal section, parte in eleva-tion, of a continuation oi sxuctnreshown in Fig. 1, ofA the leitd thereof viewed in said figure;section on the line -sc of Fig. l; n end view of the split nut used innature; and Fig, is a side view oi' the L g to the drawings, there isshown t 1 and another shaft 2 in alinernent, 7'the purposes ot thefollowing descrip- 1e shalt 1 may he considered as the .Je shalt and theshaft 2 will be considered e driven shaft. The shaft 1 ma also be deredforming one end of t e crank it of an explosive engi-ne of any suitablefpe tor the nrpose. Iny the presentilh" mance it inay je considered asof the multi- A cylinder type with means for causing the con# v ,antoperation of the engine at constant en ed onder varying loads rroin zeroload to full load that the engine can carry. iis engine in itselfforming no part of the m osent invention, and the means for'prot -dingfor constant speed under varying 'loads also 'forming no part of 'thepresent invention, not be here further considered. The iniven shaft 2may be considered -as connected to or forming part of a speed-changinggear, either of a special type which We have devised or of any othersuitable type, this shaft 2 may be considered as adr'iven shaft fortransmitting power from the drive l shaft to anyniechanism ot any kindwherein ',"there a variation oi demand for power.

Y lThe contiguous ends of the shafts 1 and 2 are formed into disi -likeheads 3 formed at the peripheries of their meeting faces with venmilarrecesses L which together constitute a halhrace for antiriction balls 5.

vfslurroundin@ the shaftsll and 2' and suitably inounte ythereon asvwill hereinafter appear is a cylindrical shell 6 reduced in diameter atone end 'to form a neck 7 which quite closely embraces the shaft 1 butis not in vcontact therewith exceptat the point 8 where there-is formeda 'hearing for this shell .upon saidl shaft.' Beyond the bearing 8 the Iy shell is again ex ended to 'form another shell or cylinder 9 dlconsiderably less diameter than the shelllyfand thisl shell has itsouter end closed by a bushing'i'secured in the. end the shell orvcylinder andsnuglytting the shaft 1 at this point. TWithin the in#terior of the cylinder 9 the shaft 1 is formed with a collar 11 fittingthe interior of the cplinder -9 quitesnugly but not sufiiciently c ose.to produce undue friction.

Bevinning close to the head 3 on the shaft 1 thetlatter 1s provided withscrew-threads 12 for an a propriete distance away from said head 3 or apur ose which will presently appear. These t reads are formed alcove thegeneral surface of the shaft to avoid weakening it and they are of avery heavy type, similar to the U. S. standard, since, as Wi lhereinafter appear, these threads' .are 'subjected to the fullstrain ofthe transmitted power.

Applied to the threaded portieri ol' the shaft 1 there is a two-part nut13 shown separately in Figsfl and 5 and the meeting edges of one of theparts beingshown in elevation in Fig. 1. This nut is formed of temperedtoolsteel andv its exterior is turned to a slight taper which matchesthe tapered end 14 of the interior of the cylinder 6 where the neck 7joins it, this taper ending in a shoulder 15. The meeting faces of thetwo halves of the nut arei ground true so: that when the nut is forcedinto the taper 14 thetwo sections of the nut will be brought intocontact attheir meeting faces. The parts are so proportioned that whenthe two sections'oi' the nut are close together there is still a slights ace between the smaller end of the nut ano the shoulder 15, asindicated at 16., thus insur# ing the rigidity of the grip between. thetaper nut and the taper portion of the cylinder 6.

The nut is split soY that the threads'may be ground true since thehardened. l y

It will be observed that the interior diameter of the threads of the nutis equal'to or slightly'greater than the exterior diameter ofthe threadson the shaft so that the threads on the nut do not enter the threads onthe shaft. In order to connect the nut and the shaft the matchingthreads are filled with .hardened steel balls 17 and the end threads ofthe nut are connected by approximately radial raceways 18 With exteriorcrossed grooves 19, shown in Fig. 5. The nut 13 is always Within-the taer portion 14 of the cylinder 6 and the wal s of this taper portionVtherefore coact with the grooves 19 to form metal of the nut is totaldriving strain of the car, which strain,

in large cars, may amount to one vhundred horse-power or more.

' rllt will be understood, ofcourse, that no vattempt is made in thedrawing to show insures an interchange of the balls so that all theballs will eventually follow all the threads during the movement of thenut. This insures equal Wear/#bn both the balls and the 'threads andmaintains the balls all ,of the saine size.

The end ofthe cylinder 6 remote from the neck is closed by a screw-,plug21 ending in a cap 22 ,abutting-f against the end of the cylinder 6.This cap may be polygonal for the ap lication of a suitable tool toscrew it into p ace or unscrew it therefrom and the direction ofthethreads on the plug 21 may be suoli that the rotation of the shaft 2will always tend to tighten the plug in its seat, thus avoiding anydanger of looseningthis .part of the structure and doing away with thenecessity of any special fastening devices. The center of the plug isbored out axially for the passage of the shaft 2, and key-ways areprovided in the plug 21 for splines 23 carried by the shaft 2. Thesesplines are 'of sufficient length to always engage in the keyways in theplug as the plug is moved longitudinally on the shaft in a mannerwhichwill hereinafter appear.'

Between the head 3 on the end of the shaft 2 and the inner end of theplug 21 there is confined a heavy helical spring 24, or, when necessary,more than one spring may be used at this point, the spring 24 beingindicative of eitherone or a number of springs.

The cylinder 6 is supported in an annular head 25 'formed on one end ofa bracket 26 coming from any suitable fixed portion of the structure towhich this invention is applied. This head is bored out to receive anumber of rings 27 confined in the head 25 by a nut 28 screwed into oneend of the bored out portion of the head 25. Between the correspondingend of the interior of the head 25 and the adjacent ring 27, and alsobetween the meeting faces of adjacent rings, and of the nut 28 andthe,ring next to it, are formed lball-races 29 filled with hardenedsteel balls 2%() bearing upon the exterior of the vcylinder 6. Betweenthe head ofthe nut 28 and the adjacent wallof the bearing head. 25 theredepending on the load.

viewed in Fig. 1.

balls and the ball-races. The nut or adjusting ring 28 may be providedwith suitable set-screws for retaining it in any adjusted position, butsuch means being a very common expedient for this purpose are notsliownin the drawings.

The exterior of the cylinder 6 may be provided with a hardened wearingsleeve upon which the balls 30 may travel, and the interior of saidcylinder may also be provided with a hardened wearing sleeve upon which'the balls 4 may travel, and the races for the balls 4 and 30 may also beformed of inserts of hardened metal, but these being structural detailsare not shown in the drawings.

Now, let it be assumed that the shaft 1 is being rotated at constantspeed by a source of 4power ample for the purpose. The eX-pansiveforce'of the spring 24 maintains the nut 13 in the taper portionof the cylinder 6. Let it further he assumed that there is no load uiponthe' shaft 2 and that the contiguous ends of the shafts 1 and 2 are atthe end of the cylinder 6 close to the nut 13 with the spring 24expanded. This will mean that the .cylinder 6 has moved t'o the right asviewed in Fig. 1 until the nut 13 is about coincident with the left-handend of the head 25. The two shafts are now rotating synchronously andthecylinder 6 is also rotating because of the connection with the shaft 2through the plug 21 and splines 23. Now, if under these circumstances aload be placed upon the shalt 2, the latter will be `either partially orwholly held against rotation, The result of this is that the cylinderwill be correspondingly held .against rotation. and the threaded portion12 of the shaft 1 will begin to screw into and rthrough the nut 13,causing the latter to engage more tightly into the taper portion 14 onthe interior of the cylinder 6 and to pull the said cylinder 6 towardthe left as This longitudinal movement of the cylinder .6* proceedsuntil the spring 24 is compressed to such an extent as to equal the loadupon the shaft 2 and the latter will then rotate, if, at the beginningof the operation, it was standing still. Under this latter suppositionthe starting torque is, of course, greater than the load after the shafthas come up to speed, and, therefore, the reaction of the spring 24 willcause the return of the cyl'nder 6 for a distance u til the parts areaga' in equilibrium. A Avari- V-ation in the loadwhile the parts arerunning will be quickly responded to by the device,

Asince it is very sensitive to any variation. But there 1s alwayssufficient time element entering into the vresponseof the device` tochanges of load to prevent shocks or jars'to tlied'riving'or drivenmachinery. In other words, there is la certain. elasticity or flexibil-fity of grip between ythe driving element find the driven elementsuflici-ent to absorb all ido shocks or jars which might otherwise occurwhen the load was applied or changed from time to time, especially wherethe application. or change of load is sudden. or takes place in a shorttime through a long range.

This invention is particularly applicable to the handling of heavy loadswhere great variations of load are liable to occur. In a car system suchvariations and violent vari'- ations of load occur'constantly, but thedevice forming vthe subject of. the present invention handles such loadswithout any gaging the ends of the interior of the cylinder 9, mayoperate as a stop for limiting the longitudinal extent of movement ofthecylinder 6.

It will be observed that the expansion and compression of the' spring 24cannot take place instantly because of the movement of the threadedshaft through the nut 13, and, therefore, even when the change of loadis sudden the compensating action of the connecting device must consumesome time,

while the'inertia of thedriven parts will alsoaid in preventing thethrowing off of the load from acting too quickly upon the cou lingdevice forming the subject-matter o the present invention.v

We claim:-

1. A owei transmission device comprising a drive shaft, a driven shaftin alinenient therewith, a member connected for rotation to and slidableon the driven shaft, a spring inter osed between thedriven. shaft andthe slida le member and inclosed by the latter, and a screw connectionbetween' the drive shaft and the slidable member.

2. A power transmission device comprising a drive shaft, a driven shafthaving one end contiguous to the corresponding end of the drive shaft,anti-friction bearings between the meeting ends of the two shaftsamember connected 4for rotation to and slidable onthe driven shaft, aspring interposed betweenI the driven shaft and the. slidable member andinclosed by the latter, and a screw connection between the drive shaftand the slide-ble member, having threads coupled by anti-friction balls.

3. A power transmission device comprising a driv shaft havingscrew-threads formed thei'een, a driven shaft in line with erases thedrive shaft, va cylinder or sleeve surround- 6 ing the meeting ends ofthe ltwo shafts and connected for rotation with and slidable on thedriven shaft and alsohaving a tapered interior portion adjacent .to thedrive shaft, a spring interposed between the driven shaft and thecylindenand a nut surroundingthe end contiguous to the drive shaft andtheref provided with an expandedhead, a cylindrical member fast forrotation, with but slidable on the driven shaft, a spring interposedbetween the expanded head of the driven shaft and the corresponding .endof the slidable member, and a nut surrounding the threaded end oi" thedrive shaft and contained in and acting on said slidable member to moveit longitudinally with relation to the shafts in opposition to theaction of the spring.

5.1%. power transmission device comprisin a drive shaft having athreaded end, a

driven shaft in line therewith, a cylindrical member connected to l thedriven shaft for rotation therewith but slidable .longitudinallythereon, a spring interposed between the` end of the driven shaft andthe corres ending end of the cylindrical member, an

. a nut carried by the threaded end of the driveI shaft, thesaidslidable member and nut coi acting for frictional engagement one withtheother to impart motion fromthe drive shaft` to the said slidablemember.l

6'. A ower transmission device comprising as aft having screw-threads4formed ,I

thereon, a split nut surrounding the same .and having a tapered.exterior, a cylinder inelosing the' threaded end of the shaft and havinga tapered seat for the nut, another shaft having one end within thecylinder and rotatively connected to said cylinder, and a springinterposed between the seeond- V f f named shaft andthe correspondingend of the cylinder.

l 7. A powertransmission device com rising a shaft having screw-threadsforme on and provided with interior' threads and exterior grooves withthrou h connections between the interior threa s and' exterior grooves,anti-hiction balls seated iiiQthd interior threads, exterior grooves andconone end, atwo-part taper nut applied thereto izo nections, a cylinderin closing the threaded"` end of the shaft and having a taper seatforthe nut and inclosing the balls contained in the enterior grooves onsaid nut,y another shaft in the axial line of the rst shaft and havingone end contained'f-in said cylinder and rotatively connected therewith,and la spring interposed between'the inclosed end o f the lastenemedshaft and the corresponding end of the cylinder. .l Y 8. A powertrensmissin deviceeom rising a. shaft heving screw-threads forme l"onone end and termineting in en ex ended ofthe shaft and the ex ended heedthereof,

e nut seated in said cy inder sind surround-H ing thefthreaded end ofthe shaft, anti-friesed between the nut-end shaft, another sv aft in theaxial line,- of the Erst-named shaft, also provided with an ex pamdedheed contained within seid cylinder,

entiefrietionbeerings between the contiguousV heads on the ends oftheshfts Land between the seme and the interior of the o linder,

means for eoupling the second sha t rotetively to the cy nder butpermittingthe la.t

ter to move Alongitndinelly on theshaft, and` a, spring' inter `osedbetween the headed end of the seconl `shaft end the vcorresponding endof the'cylinder. y l

9. A 'ower 'transmission device'compris--l ingge. n aft havingscrew-threads thereon neanone endl end'e coller 'et a ointnear seidendbut Imore remotethere rom than the screw-threads, a cylinderiiiel-csix'ig the `threaded end ofthe shaft, seidfo "linde'rhev-` ing aeontinuetion'connect'ed t ereto byJ-e neck-"andinclosin the coller onseid Shetty.' ghel threaded end of' the` Y shaft, enti-frietlon bearingsbetween'the nut Ahead, a cylinder nolosing said three ed end.

a nut inolosing `t and shaft, another shaft entering the 'eyli'n derend'rotetivel-y connected therewith sind having `its end lcontiguouswith the cror-` responding end of thefirst-named slidft,

ayntiefriotion bearings between eontig-' 'nous ends of the shaftslandthe interiorof*l the cylinder, e springfinter osedlbetween the inclosedend of the secon shaft and the 'corresponding enti-friction support forthe cylinder within which 'the yletter may rotate end move-4`longitudinally.

In testn'noinyvr as onrcwnf, we have hereto affixed our Signa,-

tuies the presence of two witnesses WILLIAM e.V MAYO, JOHN HOULEHAN.4

Witnesses: W. A. WAnNoo/K,

W. GILLEN.

end'of the cylinder,` and en? thet'we claim the foreging

